Sensory innervation of the lumbar dura mater passing through the sympathetic trunk in rats

Citation
Y. Konnai et al., Sensory innervation of the lumbar dura mater passing through the sympathetic trunk in rats, SPINE, 25(7), 2000, pp. 776-782
Citations number
29
Categorie Soggetti
Neurology
Journal title
SPINE
ISSN journal
03622436 → ACNP
Volume
25
Issue
7
Year of publication
2000
Pages
776 - 782
Database
ISI
SICI code
0362-2436(20000401)25:7<776:SIOTLD>2.0.ZU;2-U
Abstract
Study Design. Sensory innervation of the lumbar dura mater passing through the sympathetic trunk was investigated by neuronal tracing and immunohistoc hemical methods. Objective. To assess an anatomic basis indicating that sympathetic block in the higher lumbar region is effective for patients with low back pain. Summary of Background Data. Low back pain is elicited by disorder or mechan ical stimulation of the lumbar dura mater. Clinically, the authors often ha ve observed patients in whom root block at the responsible level or sympath etic block at the higher level could relieve low back pain. Therefore, ther e may be two different sensory routes, the segmental innervation at the sam e level and nonsegmental fibers from higher dorsal root ganglia. Methods. The tracers were injected into the sympathetic trunk between L3 an d L4 of rats. The lumbar dorsal root ganglia and dura mater were examined, and labeled cells were measured in size and the distribution. To establish the sensory property, the materials were processed in immunohistochemistry for calcitonin gene-related peptide. Results. Many small- to medium-sized neurons were retrogradely labeled L1 a nd L2 dorsal root ganglia after injection into the sympathetic trunk. The a nterogradely labeled fibers were found in the dura mater at L4 and L5. Some of the labeled neurons and fibers were immunoreactive for calcitonin gene- related peptide. Conclusion. Sensory fibers from the upper lumbar ganglia innervated the low er lumbar dura mater directly. These sensory nerves may mediate low back pa in and possibly interact with sympathetic nerves.